Which environmental factor can affect the rate of enzyme activity?

The rate of enzyme activity is significantly influenced by temperature. Enzymes function optimally at specific temperature ranges, known as their temperature optima. Within this optimal range, the kinetic energy of molecules increases, leading to more frequent collisions between enzymes and substrates, thereby enhancing reaction rates. However, if the temperature becomes too high, enzymes can denature, losing their three-dimensional structure and, consequently, their ability to catalyze reactions. On the other hand, at very low temperatures, enzyme activity can slow down significantly due to reduced molecular motion.

While pH levels can also affect enzyme activity, as each enzyme has a specific pH at which it operates best, the question specifically focuses on a single environmental factor, making temperature the most definitive choice in general enzyme activity discussions. Light intensity and humidity, though they can affect biological processes, do not have a direct and specific impact on the rate of enzyme activity like temperature does.